Investigation on Doppler spectra of microwave scattering from sea surface
Investigation on Doppler spectra of microwave scattering from sea surface
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海面微波散射多普勒谱研究
DOI：
10.7498/aps.61.124213
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发表时间：
2012-06
影响因子：
1
通讯作者：
Zhang Yan-Min
中科院分区：
文献类型：
--
作者：
Jiang Wen-Zheng;Yuan Ye-Li;Wang Yun-Hua;Zhang Yan-Min
基于复合海面散射模型，推导了时变海面雷达回波多普勒频移和带宽的解析表达式。在推导过程中，考虑了倾斜调制、阴影和大尺度起伏波曲率的影响，得到了更合理的结果。理论计算结果与直接数值模拟结果的比较表明，该解析公式能显著改善模拟结果。详细讨论了倾斜调制、阴影和曲率对多普勒频谱特性的影响。从模拟结果中，它被发现，预测的多普勒频移总是在HH偏振大于VV偏振，由于大尺度波的倾斜调制。此外，在低掠射角下，大尺度波的阴影会导致多普勒频移的快速增加，相反会使带宽变窄。
Based on the composite surface scattering model, the analytical formulas for Doppler shift and bandwidth of radar echoes return from time-varying sea surface are derived. In our derivations, the influences of the tilt modulation, the shadow and the curvature of large-scale undulating waves are all taken into account for achieving more reasonable results. Comparisons between the theoretical results and direct numerical simulations demonstrate that the analytical formulas can significantly improve the simulated results. And the effects of the tilt modulation, the shadow and the curvature on Doppler spectral properties are discussed in detail. From the simulated results, it is found that the predicted Doppler shifts are always larger in HH-polarization than in VV-polarization due to the tilt modulation of large-scale waves. In addition, at low-grazing angles, the shadow of large-scale waves results in a rapid increase of the predicted Doppler shift, and on the contrary maks the bandwidth narrower.